Senate Majority Leader Mitch McConnell delayed a vote to repeal and replace Obamacare scheduled for early next week after Sen. John McCain announced he’d be out due to surgery, costing Republicans sufficient votes to move forward.

McConnell gave no new timetable for the vote when he announced the delay late Saturday, saying only that the the Senate will “defer consideration” of the bill while working on other matters. GOP Sens. Rand Paul of Kentucky and Susan Collins of Maine opposed the bill already, and McCain’s absence next week would likely have made it impossible to proceed.

A half-dozen key senators, including McCain, were undecided on whether to go ahead with a procedural vote, putting the bill’s future in serious jeopardy before McConnell punted.

McCain revealed on Saturday that he had a blood clot removed on Friday at the Mayo Clinic Hospital in Phoenix. His office said he would spend next week in Arizona recovering from the surgery, leaving McConnell short of the votes to move forward. Republicans control only 52 votes in the chamber, and the early opposition to the bill from Collins and Paul means McConnell can’t afford to lose any more votes from his party given the united Democratic opposition.